A fuel cell is an energy conversion device that converts chemical energy into electricity, and a proton exchange membrane fuel cell (PEMFC) operating at a low temperature has been receiving more and more attention. Because of the difficulty of hydrogen storage associated with PEMFC, direct methanol fuel cells (DMFC) and direct ethanol fuel cell (DEFC) are known to be more advantageous than PEMFC. However, two key issues limit the commercialization of DMFC, the first being low efficiency and the second being the poor stability of its catalyst.
Platinum (Pt) is the most popular catalyst for anode and cathode for use in DMFC, but Pt is an expensive noble metal and is easily poisoned by carbonaceous intermediates, leading to the reduction of catalytic stability. For this reason, alloying 3d transition metals with Pt or other noble metals, such as palladium (Pd) is a possible alternative, and thus Pd is often used as an anode catalyst in DMFC. However, Pd or Pd-based component catalysts may also exhibit poor stability if they suffer from the same “poisoning effect” as Pt. To solve the stability problem, black carbon is used as an inexpensive support. However, black carbon becomes unstable after several cycles of electro-oxidation reaction.
It is thus an object of the present invention to provide a method of fabricating a nanoporous metal structure, a nanoporous metal structure fabricated by such a method, and a fuel cell including such a nanoporous metal structure, in which the aforesaid shortcomings are mitigated or at least to provide a useful alternative to the trade and public.